Modular intraocular lens designs and methods

ABSTRACT

A modular IOL system including intraocular primary and secondary components, which, when combined, form an intraocular optical correction device, wherein the secondary component is placed on the primary component within the perimeter of the capsulorhexis, thus avoiding the need to touch or otherwise manipulate the capsular bag. The secondary component may be manipulated, removed, and/or exchanged for a different secondary component for correction or modification of the optical result, on an intra-operative or post-operative basis, without the need to remove the primary component and without the need to manipulate the capsular bag. The primary component may have haptics extending therefrom for centration in the capsular bag, and the secondary component may exclude haptics, relying instead on attachment to the primary lens for stability. Such attachment may reside radially inside the perimeter of the capsulorhexis and radially outside the field of view to avoid interference with light transmission.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 13/748,207filed on Jan. 23, 2013, which claims the benefits under 35 U.S.C.§119(e) of priority of U.S. Provisional Patent Application No.61/589,981 filed on Jan. 24, 2012, entitled “LASER ETCHING OF IN SITUINTRAOCULAR LENS AND SUCCESSIVE SECONDARY LENS IMPLANTATION,” and ofU.S. Provisional Patent Application No. 61/677,213 filed on Jul. 30,2012, entitled “MODULAR INTRAOCULAR LENS DESIGNS & METHODS,” each ofwhich is incorporated herein by reference.

FIELD OF THE INVENTION

The present disclosure generally relates to embodiments of intraocularlenses (IOLs). More specifically, the present disclosure relates toembodiments of modular IOL designs and methods.

BACKGROUND

The human eye functions to provide vision by transmitting light througha clear outer portion called the cornea, and focusing the image by wayof a crystalline lens onto a retina. The quality of the focused imagedepends on many factors including the size and shape of the eye, and thetransparency of the cornea and the lens.

When age or disease causes the lens to become less transparent (e.g.,cloudy), vision deteriorates because of the diminished light, which canbe transmitted to the retina. This deficiency in the lens of the eye ismedically known as a cataract. An accepted treatment for this conditionis surgical removal of the lens from the capsular bag and placement ofan artificial intraocular lens (IOL) in the capsular bag. In the UnitedStates, the majority of cataractous lenses are removed by a surgicaltechnique called phacoemulsification. During this procedure, an opening(capsulorhexis) is made in the anterior side of the capsular bag and athin phacoemulsification-cutting tip is inserted into the diseased lensand vibrated ultrasonically. The vibrating cutting tip liquefies oremulsifies the lens so that the lens may be aspirated out of thecapsular bag. The diseased lens, once removed, is replaced by an IOL.

After cataract surgery to implant an IOL, the optical result may besuboptimal or may need adjustment over time. For example, shortly afterthe procedure, it may be determined that the refractive correction iserroneous leading to what is sometimes called “refractive surprise.”Also for example, long after the procedure, it may be determined thatthe patient needs or desires a different correction, such as a strongerrefractive correction, an astigmatism correction, or a multifocalcorrection.

In each of these cases, a surgeon may be reluctant to attempt removal ofthe suboptimal IOL from the capsular bag and replacement with a new IOL.In general, manipulation of the capsular bag to remove an IOL risksdamage to the capsular bag including posterior rupture. This riskincreases over time as the capsular bag collapses around the IOL andtissue ingrowth surrounds the haptics of the IOL. Thus, it would bedesirable to be able to correct or modify the optical result without theneed to remove the IOL or manipulate the capsular bag.

A variety of secondary lenses have been proposed to address theaforementioned drawbacks. For example, one possible solution includes asecondary lens that resides anterior to the capsular bag with hapticsthat engage the ciliary sulcus. While this design may have the advantageof avoiding manipulation of the capsular bag, its primary disadvantageis engaging the ciliary sulcus. The ciliary sulcus is composed of softvascularized tissue that is susceptible to injury when engaged byhaptics or other materials. Such injury may result in complications suchas bleeding, inflammation and hyphema. Thus, in general, it may bedesirable to avoid placing a secondary lens in the ciliary sulcus toavoid the potential for complications.

Another potential solution may include a lens system that avoids thepotential problems associated with the ciliary sulcus. The lens systemmay include a primary lens and a secondary lens, where the secondarylens may be attached to the primary lens, both within the capsular bag.The primary lens may have a recess into which an edge of the secondarylens may be inserted for attachment. The recess is preferably locatedradially outwardly of the opening (capsulorhexis) in the capsular bag toavoid interfering with light transmission. To attach the secondary lensin-situ, the capsular bag must be manipulated around the perimeter ofthe capsulorhexis to gain access to the recess in the primary lens. Asstated previously, manipulation of the capsular bag may be undesirablegiven the risks associated therewith. Therefore, while such lens systemsmay avoid the potential for injury to the ciliary sulcus by implantingboth the primary lens and the secondary lens in the capsular bag, thesesystems do not avoid manipulation of the capsular bag to attach thesecondary lens.

Thus, there remains a need for an IOL system and method that allows forcorrection or modification of the optical result using a secondary lensthat can be attached to a primary lens without the need manipulate thecapsular bag.

SUMMARY OF THE INVENTION

Embodiments of the present disclosure provide a modular IOL systemincluding intraocular primary and secondary components, which, whencombined, form an intraocular optical correction device. The primarycomponent may comprise an intraocular base, and the secondary componentmay comprise an intraocular lens, wherein the base is configured toreleasably receive the intraocular lens. In some embodiments, the basemay be configured as a lens, in which case the modular IOL system may bedescribed as including a primary lens and a secondary lens. The primarycomponent (e.g., base or primary lens) may be placed in the capsular bagusing conventional cataract surgery techniques. The primary componentmay have a diameter greater than the diameter of the capsulorhexis toretain the primary component in the capsular bag. The secondarycomponent (e.g., secondary lens) may have a diameter less than thediameter of the capsulorhexis such that the secondary component may beattached to the primary component without manipulation of the capsularbag. The secondary component may also be manipulated to correct ormodify the optical result, intra-operatively or post-operatively,without the need to remove the primary component and without the need tomanipulate the capsular bag. For example, the secondary component may beremoved, repositioned, and/or exchanged to correct, modify, and/or finetune the optical result.

Common indications for exchanging the secondary component may beresidual refractive error (e.g., for monofocal lenses), decentrationerror (e.g., for multifocal lenses) due to post-operative healing,astigmatism error (e.g., for toric lenses) induced by surgery, changingoptical correction needs due to progressive disease, changing opticalcorrection desires due to lifestyle changes, injury, age, etc.

The primary component may have haptics (e.g., projections) extendingtherefrom for centration in the capsular bag, and the secondarycomponent may exclude haptics, relying instead on attachment to theprimary component for stability. Such attachment may reside radiallyinside the perimeter of the capsulorhexis and radially outside the fieldof view to avoid interference with light transmission. Alternatively orin addition, the attachment may comprise a small fraction of theperimeter (e.g., less than 20%) of the secondary component to minimizethe potential for interference in light transmission.

The primary component may have an anterior surface that is in intimatecontact with a posterior surface of the secondary component to preventfluid ingress, tissue ingrowth, and/or optical interference. Thesecondary component may be removably secured to the primary component bymechanical attachment and/or chemical attraction, for example.Mechanical attachment may be facilitated by mating or interlockinggeometries corresponding to each of the primary and the secondarycomponents. Such geometries may be pre-formed by molding or cutting, forexample, or formed in-situ by laser etching, for example. Chemicalattraction may be facilitated by using similar materials with a smoothsurface finish activated by a surface treatment, for example. In someinstances, it may be desirable to reduce chemical attraction and relymore on mechanical attachment for stability. In this case, the primaryand secondary components may be formed of dissimilar materials orotherwise have adjacent surfaces that do not have a chemical attraction.

The modular IOL systems and methods according to embodiments of thepresent disclosure may be applied to a variety of IOL types, includingfixed monofocal, multifocal, toric, accommodative, and combinationsthereof. In addition, the modular IOL systems and methods according toembodiments of the present disclosure may be used to treat, for example:cataracts, large optical errors in myopic (near-sighted), hyperopic(far-sighted), and astigmatic eyes, ectopia lentis, aphakia,pseudophakia, and nuclear sclerosis.

Various other aspects of embodiments of the present disclosure aredescribed in the following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate example embodiments of the present disclosure.The drawings are not necessarily to scale, may include similar elementsthat are numbered the same, and may include dimensions (in millimeters)and angles (in degrees) by way of example, not necessarily limitation.In the drawings:

FIG. 1 is a schematic diagram of the human eye shown in cross section;

FIGS. 2A and 2B are front and side cross-sectional views, respectively,of a modular IOL disposed in a capsular bag according to an embodimentof the present disclosure;

FIGS. 3A-3D and 4A-4D are front and side cross-sectional views,respectively, schematically illustrating a method for implanting amodular IOL according to an embodiment of the present disclosure;

FIG. 5 is a front view of a modular IOL, according to an embodiment ofthe present disclosure, wherein subsurface attachment mechanisms areprovided for connection between the primary and secondary lenses;

FIGS. 6A and 6B are cross-sectional views taken along line 6-6 in FIG.5, showing two embodiments of subsurface attachment mechanisms;

FIG. 7 is a front view of a modular IOL, according to an embodiment ofthe present disclosure, wherein extension attachment mechanisms areprovided to connect the primary and secondary lenses;

FIGS. 8A-8C are cross-sectional views taken along line 8-8 in FIG. 7,showing three embodiments of extension attachment mechanisms;

FIGS. 9A-9D are front views showing various positions of the attachmentmechanisms to adjust the position of the secondary lens relative to theprimary lens;

FIG. 10 is a front view of a modular IOL, according to an embodiment ofthe present disclosure, wherein etched subsurface attachment mechanismsare provided for connection between the primary and secondary lenses;

FIGS. 11A-11F are cross-sectional views of the modular IOL shown in FIG.10, showing various embodiments of etched subsurface attachmentmechanisms;

FIGS. 12A-12C are schematic illustrations of front, sectional and detailviews, respectively, of an alternative modular IOL, according to anembodiment of the present disclosure;

FIGS. 13A and 13B show representative photomicrographs at 4× and 40×magnification, respectively, of a groove (see, arrow) formed by laseretching;

FIGS. 14-22 and 22A-22D are various views of alternative modular IOLsaccording to embodiments of the present disclosure;

FIGS. 23A-23D are schematic illustrations of a lens removal system for amodular IOL according to an embodiment of the present disclosure;

FIG. 24 is a schematic flow chart of a method for using a modular IOL,according to an embodiment of the present disclosure, wherein anexchange of the secondary lens is motivated by a sub-optimal opticalresult detected intra-operatively;

FIG. 25 is a schematic flow chart of a method for using a modular IOL,according to an embodiment of the present disclosure, wherein anexchange of the secondary lens is motivated by a sub-optimal opticalresult detected post-operatively;

FIG. 26 is a schematic flow chart of a method for using a modular IOL,according to an embodiment of the present disclosure, wherein asecondary lens is attached to a primary lens by forming the attachmentmeans in-situ; and

FIGS. 27 and 27A-27D are various views of a further embodiment of amodular IOL, according to the present disclosure.

DETAILED DESCRIPTION

With reference to FIG. 1, the human eye 10 is shown in cross section.The eye 10 has been described as an organ that reacts to light forseveral purposes. As a conscious sense organ, the eye allows vision. Rodand cone cells in the retina 24 allow conscious light perception andvision including color differentiation and the perception of depth. Inaddition, the human eye's non-image-forming photosensitive ganglioncells in the retina 24 receive light signals which affect adjustment ofthe size of the pupil, regulation and suppression of the hormonemelatonin, and entrainment of the body clock.

The eye 10 is not properly a sphere; rather it is a fused two-pieceunit. The smaller frontal unit, more curved, called the cornea 12 islinked to the larger unit called the sclera 14. The corneal segment 12is typically about 8 mm (0.3 in) in radius. The sclera 14 constitutesthe remaining five-sixths; its radius is typically about 12 mm. Thecornea 12 and sclera 14 are connected by a ring called the limbus. Theiris 16, the color of the eye, and its black center, the pupil, are seeninstead of the cornea 12 due to the cornea's 12 transparency. To seeinside the eye 10, an ophthalmoscope is needed, since light is notreflected out. The fundus (area opposite the pupil), which includes themacula 28, shows the characteristic pale optic disk (papilla), wherevessels entering the eye pass across and optic nerve fibers 18 departthe globe.

Thus, the eye 10 is made up of three coats, enclosing three transparentstructures. The outermost layer is composed of the cornea 12 and sclera14. The middle layer consists of the choroid 20, ciliary body 22, andiris 16. The innermost layer is the retina 24, which gets itscirculation from the vessels of the choroid 20 as well as the retinalvessels, which can be seen within an ophthalmoscope. Within these coatsare the aqueous humor, the vitreous body 26, and the flexible lens 30.The aqueous humor is a clear fluid that is contained in two areas: theanterior chamber between the cornea 12 and the iris 16 and the exposedarea of the lens 30; and the posterior chamber, between the iris 16 andthe lens 30. The lens 30 is suspended to the ciliary body 22 by thesuspensory ciliary ligament 32 (Zonule of Zinn), made up of finetransparent fibers. The vitreous body 26 is a clear jelly that is muchlarger than the aqueous humor.

The crystalline lens 30 is a transparent, biconvex structure in the eyethat, along with the cornea 12, helps to refract light to be focused onthe retina 24. The lens 30, by changing its shape, functions to changethe focal distance of the eye so that it can focus on objects at variousdistances, thus allowing a sharp real image of the object of interest tobe formed on the retina 24. This adjustment of the lens 30 is known asaccommodation, and is similar to the focusing of a photographic cameravia movement of its lenses.

The lens has three main parts: the lens capsule, the lens epithelium,and the lens fibers. The lens capsule forms the outermost layer of thelens and the lens fibers form the bulk of the interior of the lens. Thecells of the lens epithelium, located between the lens capsule and theoutermost layer of lens fibers, are found predominantly on the anteriorside of the lens but extend posteriorly just beyond the equator.

The lens capsule is a smooth, transparent basement membrane thatcompletely surrounds the lens. The capsule is elastic and is composed ofcollagen. It is synthesized by the lens epithelium and its maincomponents are Type IV collagen and sulfated glycosaminoglycans (GAGs).The capsule is very elastic and so causes the lens to assume a moreglobular shape when not under the tension of the zonular fibers, whichconnect the lens capsule to the ciliary body 22. The capsule variesbetween approximately 2-28 micrometers in thickness, being thickest nearthe equator and thinnest near the posterior pole. The lens capsule maybe involved with the higher anterior curvature than posterior of thelens.

Various diseases and disorders of the lens 30 may be treated with anIOL. By way of example, not necessarily limitation, a modular IOLaccording to embodiments of the present disclosure may be used to treatcataracts, large optical errors in myopic (near-sighted), hyperopic(far-sighted), and astigmatic eyes, ectopia lentis, aphakia,pseudophakia, and nuclear sclerosis. However, for purposes ofdescription, the modular IOL embodiments of the present disclosure aredescribed with reference to cataracts.

The following detailed description describes various embodiments of amodular IOL system including primary and secondary intraocularcomponents, namely an intraocular base configured to releasably receivean intraocular lens. In some embodiments, the base may be configured toprovide optical correction, in which case the modular IOL system may bedescribed as including a primary lens and a secondary lens. Theprinciples and features described with reference to embodiments wherethe base is configured for optical correction may be applied toembodiments where the base is not configured for optical correction, andvice versa. Stated more broadly, features described with reference toany one embodiment may be applied to and incorporated into otherembodiments.

With reference to FIGS. 2A and 2B, a modular IOL system 50/60 is shownimplanted in the capsular bag 34 of lens 30 having a capsulorhexis 36formed therein. The modular IOL system may include a primary lens 50 anda secondary lens 60. The primary lens 50 may include a body portion 52,a pair of haptics 54 for anchoring and centering the primary lens 50 inthe capsular bag 34, and means for attachment (not shown here, butdescribed later) to the secondary lens 60. The secondary lens 60 mayinclude an optic body portion 62, no haptics, and corresponding meansfor attachment (not shown here, but described later) to the primary lens50. The anterior surface of the body portion 52 of the primary lens 50may be in intimate contact with the posterior surface of the bodyportion 62 of the secondary lens 60, without any intervening material(e.g., adhesive, aqueous humor, tissue ingrowth, etc.) in between. Forexample, the anterior surface of the body portion 52 may be in directedcontact with the posterior surface of body portion 62. The secondarylens 60 may be acutely and chronically releasably attached to theprimary lens 50 to facilitate exchange of the secondary lens 60 whilethe primary lens 50 remains in the capsular bag 34 of the lens 30.

The body portion 52 of the primary lens 50 may provide some refractivecorrection, but less than required for an optimal optical result. Theoptimal optical result may be provided by the combination of thecorrection provided by the optical body portion 52 of the primary lens50 together with the optical body portion 62 of the secondary lens 60.For example, the optical body portion 62 of the secondary lens 60 maychange (e.g., add or subtract) refractive power (for monofocalcorrection), toric features (for astigmatism correction), and/ordiffractive features (for multifocal correction).

The secondary lens 60 may have an outside diameter d1, the capsulorhexis36 may have an inside diameter d2, and the body 52 of the primary lens50 may have an outside diameter d3, where d1<d2≦d3. This arrangementprovides a gap between the secondary lens 60 and the perimeter of thecapsulorhexis 36 such that the secondary lens 60 may be attached ordetached from the primary lens 50 without touching or otherwisedisturbing any portion of the capsular bag 34. By way of example, notlimitation, assuming the capsulorhexis has a diameter of approximately 5to 6 mm, the body of the primary lens (i.e., excluding the haptics) mayhave a diameter of approximately 5 to 8 mm, and the secondary lens mayhave a diameter of approximately 3 to less than 5 mm, thereby providinga radial gap up to approximately 1.5 mm between the secondary lens andthe perimeter of the capsulorhexis. Notwithstanding this example, anysuitable dimensions may be selected to provide a gap between thesecondary lens and the perimeter of the capsulorhexis in order tomitigate the need to manipulate the lens capsule to attach the secondarylens to the primary lens.

With reference to FIGS. 3A-3D (front views) and 4A-4D (sidecross-sectional views), a method for implanting a modular IOL system50/60 is shown schematically. As seen in FIGS. 3A and 4A, a lens 30 withcataracts includes an opaque or clouded center 38 inside a capsular bag34. Access to the lens 30 for cataract surgery may be provided by one ormore lateral incisions in the cornea. A capsulorhexis (circular hole) 36may be formed in the anterior capsular bag 34 using manual tools or afemtosecond laser. As seen in FIGS. 3B and 4B, the opaque center 38 isremoved by phacoemulsification and/or aspiration through thecapsulorhexis 36. The primary lens 50 is delivered in a rolledconfiguration using a tube inserted through the capsulorhexis 36 andinto the capsular bag 34. The primary lens 50 is ejected from thedelivery tube and allowed to unfurl. With gentle manipulation, thehaptics 54 of the primary lens engage the inside equator of the lenscapsule 34 and center the lens body 52 relative to the capsulorhexis 36as seen in FIGS. 3C and 4C. The secondary lens 60 is delivered in arolled configuration using a tube, positioning the distal tip thereofadjacent the primary lens 50. The secondary lens 60 is ejected from thedelivery tube and allowed to unfurl. With gentle manipulation, thesecondary lens 60 is centered relative to the capsulorhexis 36. Withoutmanipulating the capsular bag 34 or the primary lens 50, the secondarylens 60 is then attached to the primary lens 50 as seen in FIGS. 3D and4D. If necessary, the secondary lens 60 may be removed and/or replacedin a similar manner, reversing the steps where appropriate. As analternative, the primary 50 and secondary 60 lenses may be implanted asa unit, thus eliminating a delivery step.

Because it may be difficult to ascertain which side of the secondarylens 60 should face the primary lens 50, the secondary lens may includea marking indicative of proper position. For example, a clockwise arrowmay be placed along the perimeter of the anterior surface of thesecondary lens 60, which appears as a clockwise arrow if positionedright-side-up and a counter-clockwise arrow if positioned wrong-side-up.Alternatively, a two-layered color marking may be placed along theperimeter of the anterior surface of the secondary lens 60, whichappears as a first color if positioned right-side-up and a second colorif positioned wrong-side-down. Other positionally indicative markingsmay be employed on the secondary lens 60, and similar marking schemesmay be applied to the primary lens 50.

With reference to FIG. 5, subsurface attachment mechanisms 70 may beused to releasably secure the secondary lens 60 to the primary lens 50.The attachment mechanisms 70 may be positioned radially inside theperimeter of the capsulorhexis 36 and radially outside the field of viewto avoid interference with light transmission. Alternatively or inaddition, the attachment mechanism 70 may have radial and lateralextents limited to a small fraction (e.g., less than 10-20%) of theperimeter of the secondary lens 50 to minimize the potential forinterference in light transmission. Two diametrically opposed attachmentmechanisms 70 are shown, but any suitable number may be used, uniformlyor non-uniformly distributed about the circumference of the secondarylens 60.

If the primary lens 50 and the secondary lens 60 are delivered at thesame time, it may be desirable to align the attachment mechanisms 70with the roll axis 80, around which the lenses 50 and 60 may be rolledfor insertion via a delivery tool. Because the secondary lens 60 mayshift relative to the primary lens 50 when rolled about axis 80,providing the attachment mechanisms 70 along the roll axis 80 minimizesstress to the attachment mechanisms 70. To this end, the attachmentmechanisms 70 may be coaxially aligned relative to the roll axis 80 andmay be configured to extend a limited distance (e.g., less than 10-20%of the perimeter of the secondary lens 60) from the axis 80.

The attachment mechanisms 70 may be configured to have mating orinterlocking geometries as shown in FIGS. 6A and 6B. Generally, thegeometries include a male portion and female portion that are releasablyconnectable. The female portion is configured to receive the maleportion and limit relative motion between the primary lens 50 and thesecondary lens 60 in at least two dimensions (e.g., superior-inferiorand right-left). The female and male portions may be configured to havean interlocking geometry such that relative motion between the primarylens 50 and the secondary lens 60 is limited in three dimensions (e.g.,superior-inferior, right-left, anterior-posterior). The attachmentmechanisms 70 may be engaged and disengaged by applying orthogonal forcein a posterior (push) and anterior (pull) direction, respectively. Theattachment mechanisms 70 may be pre-formed by molding, cutting, etching,or a combination thereof, for example.

In the examples shown, each attachment mechanism 70 comprises aninterlocking cylindrical protrusion 72 and cylindrical recess or groove74. Other mating or interlocking geometries may be used as well. Thecylindrical geometry shown has the advantage of allowing slight rotationof the secondary lens 60 relative to the primary lens 50 when rolled fordelivery, thus further reducing stress thereon. As shown in FIG. 6A, thecylindrical protrusion 72 may extend anteriorly from the anteriorsurface of the body 52 of the primary lens 50, and the cylindricalrecess 74 may extend anteriorly through the posterior surface of thebody 62 of the secondary lens 60 adjacent a radial peripheral zonethereof. Alternatively, as shown in FIG. 6B, the cylindrical protrusion72 may extend posteriorly from the posterior surface of the body 62 ofthe secondary lens 60 adjacent a radial peripheral zone thereof, and thecylindrical recess 74 may extend posteriorly through the anteriorsurface of the body 52 of the primary lens 50. The configuration shownin FIG. 6B may be particularly suited for the case where the primarylens 50 is a pre-existing implanted IOL into which the recess 74 may beetched in-situ, by laser, for example.

With reference to FIG. 7, extension attachment mechanisms 90 may be usedto releasably connect the primary 50 and secondary 60 lenses. Extensionattachment mechanisms 90 may be similar to subsurface attachmentmechanisms 70 except as shown and described. Extension attachmentmechanisms 90 may extend radially from the perimeter of the secondarylens 60, with each including mating or interlocking geometries, examplesof which are shown in FIGS. 8A-8C. In FIG. 8A, a cylindrical portion 92extends from the outer edge of the secondary lens 60, and a cylindricalrecess 94 extends from the outer edge of the primary lens 50. In FIG.8B, the corollary is shown, with the cylindrical portion 92 extendingfrom the outer edge of the primary lens 50, and the cylindrical recess94 extending from the outer edge of the secondary lens 60. In bothembodiments shown in FIGS. 8A and 8B, the attachment mechanisms 90 maybe engaged and disengaged by applying orthogonal force in a posterior(push) and anterior (pull) direction, respectively. Alternatively, inthe embodiment shown in FIG. 8C, the attachment mechanisms 90 may beengaged and disengaged by applying rotational force in a clockwise orcounterclockwise direction, depending on which lens 50/60 is attached toeach of the cylindrical portion 92 and the cylindrical recess 94. Inaddition, although the embodiment of FIG. 7 only depicts the use of twoattachment mechanisms 90, any suitable number of attachment mechanisms90 may be utilized within the principles of the present disclosure.

With reference to FIGS. 9A-9D, the portion of attachment mechanism 90associated with the secondary lens 60 may be positioned such that thecenter of the secondary lens 60 is aligned with the center of theprimary lens 50. Alternatively, to adjust for misalignment of theprimary lens 50 due to imbalanced post-operative healing, for example,the portion of attachment mechanism 90 associated with the secondarylens 60 may be offset as shown in FIGS. 9B-9D. In FIG. 9B, the portionof attachment mechanism 90 associated with the secondary lens 60 isrotationally offset. In FIG. 9C, the portion of attachment mechanism 90associated with the secondary lens 60 is superiorly offset. In FIG. 9D,the portion of attachment mechanism 90 associated with the secondarylens 60 is laterally offset. An anterior-posterior offset may also beemployed as described in more detail with reference to FIGS. 11C and11F. Each of the embodiments shown in FIGS. 9B, 9C, 9D, 11C and 11F areprovided by way of example, and the offset may be made in any direction(anterior, posterior, superior, inferior, right, left, clockwise,counterclockwise) or combination thereof, to varying magnitudesdepending on the misalignment of the primary lens 50. In addition,attachment mechanism 90 is shown by way of example, but the sameprinciples may be applied to other attachment means described herein.

With reference to FIG. 10, alternative subsurface attachment mechanisms100 may be used to releasably connect the secondary lens 50 to theprimary lens 60. Subsurface attachment mechanisms 100 may be similar tosubsurface attachment mechanisms 70 except as shown and described.Subsurface attachment mechanisms 100 may comprise mating or interlockinggeometries extending along an arcuate path adjacent the peripheral edgeof the secondary lens 60. The subsurface attachment mechanism 100 mayinclude a protrusion 102 and a corresponding recess or groove 104 intowhich the protrusion 102 may be received. The protrusion 102 may extendfrom the posterior surface of the secondary lens 60 and thecorresponding recess or groove 104 may extend into the anterior surfaceof the primary lens 50 as shown in FIGS. 11A (separated) and 11D(attached). Alternatively, the protrusion 102 may extend from theanterior surface of the primary lens 50 and the corresponding the recessor groove 104 may extend into the posterior surface of the secondarylens 60 as shown in FIGS. 11B (separated) and 11E (attached). In eitherembodiment, the anterior-posterior dimension of the protrusion 102 maymatch the same dimension of the recess or groove 104 to provide intimatecontact between the anterior surface of the primary lens 50 and theposterior surface of the secondary lens 60. Alternatively, theanterior-posterior dimension of the protrusion 102 may exceed the samedimension of the recess or groove 104 to provide an anterior-posterioroffset as shown in FIGS. 11C (separated) and 11F (attached). Further,those of ordinary skill in the art will readily recognize that anysuitable number of attachment mechanisms 100 may be utilized within theprinciples of the present disclosure.

With reference to FIG. 12A, alternative subsurface attachment mechanisms105 may be used to connect the secondary lens 60 to the primary lens 50.Subsurface attachment mechanisms 105 may be similar to subsurfaceattachment mechanisms 100 except as shown and described. As seen in FIG.12B, which is a cross-sectional view taken along line B-B in FIG. 12A,the subsurface attachment mechanism 105 may comprise mating orinterlocking geometries including a protrusion 107 and a series of holes109 into which the protrusion 107 may be received. The holes 109 may bedistributed in a pattern as seen in FIG. 12C, which shows severalalternative detail views of box C in FIG. 12A. In FIG. 12C, theprotrusion 107 resides in a hole 109 designated as a black circle whilethe remaining holes 109 designated as white circles remain open. Withthis arrangement, the protrusions 107 may be placed in a correspondingpair of holes 109 to achieve the desired alignment between the primary50 and secondary 60 lenses. For example, and with continued reference toFIG. 12C, the protrusions 107 may be placed in a corresponding pair ofholes 109 to achieve centered (nominal), shift right, shift left, shiftup, shift down, rotate clockwise or rotate counterclockwise (labeledC1-C7, respectively) alignment between the primary 50 and secondary 60lenses. This arrangement provides a range of adjustments as describedwith reference to FIGS. 9A-9D. In addition, any suitable number ofattachment mechanisms 105 may be disposed uniformly or non-uniformlyabout a perimeter of lenses 50 and 60.

All or a portion of the various subsurface attachment means describedherein may be formed by molding, cutting, milling, etching or acombination thereof. For example, with particular reference to FIG. 11A,the groove 104 may be formed by in-situ, laser etching a pre-existingimplanted primary lens 50, and the protrusion may be pre-formed bymolding, milling or cutting the secondary lens 60.

Examples of lasers that may be used for in-situ etching includefemtosecond lasers, ti/saph lasers, diode lasers, YAG lasers, argonlasers and other lasers in the visible, infrared and ultraviolet range.Such lasers may be controlled in terms of energy output, spatial controland temporal control to achieve the desired etch geometry and pattern.In-situ etching may be accomplished, for example, by transmitting alaser beam from an external laser source, through the cornea and pastthe pupil. Alternatively, in-situ etching may be accomplished bytransmitting a laser beam from a flexible fiber optic probe insertedinto the eye.

With reference to FIGS. 13A and 13B, photomicrographs at 4× and 40×magnification, respectively, show how a groove (see, arrow) wasexperimentally etched in a primary lens by laser etching. A femtosecondlaser set within the following ranges may be used to etch the groove:power of 1 nJ to 100 uJ; pulse duration of 20 fs up to the picosecondrange; and a frequency of 1 to 250 kHz.

The primary and secondary components of the modular IOL systemsdisclosed herein may be formed of the same, similar or dissimilarmaterials. Suitable materials may include, for example, acrylate-basedmaterials, silicone materials, hydrophobic polymers or hydrophilicpolymers, and such materials may have shape-memory characteristics. Forexample, materials comprising the optical portions of the modular lenssystem can be silicone, PMMA, hydrogels, hydrophobic acrylic,hydrophilic acrylic or other transparent materials commonly used forintraocular lenses. Non-optical components of the modular IOL mightinclude nitinol, polyethylene sulfone and/or polyimide.

Materials can be selected to aid performance of certain features of themodular lens system notably the attachment and detachment featuresnecessary for the primary and secondary lenses as previously described.Other features of the modular lens that can be enhanced with specificmaterial selections include manufacturability, intraoperative andpost-operative handling, fixation (both intraoperative and at time ofpost-operative modification), reaching micro-incision sizes (≦2.4 mm)and exchangeability (minimal trauma on explantation of lenses).

For example, in one embodiment the primary lens and the secondary lensare made from hydrophobic acrylic material having a glass transitiontemperature between approximately 5 and 30° C. and a refractive indexbetween approximately 1.41-1.60. In another embodiment, the primary andsecondary lens can be made from different materials having differentglass transition temperatures and mechanical properties to aid fixationand detachment properties of the modular system. In another embodiment,both or either of the modular lens system is made from materialsallowing for compression to an outer diameter equal to or smaller thanapproximately 2.4 mm.

Material properties that are generally desirable in the modular IOLsystem include minimal to no glistening formation, minimal pitting whenexposed to YAG laser application and passing standard MEM elutiontesting and other biocompatibility testing as per industry standards.The material may contain various chromophores that will enhance UVblocking capabilities of the base material. Generally, wavelengths thatare sub 400 nm are blocked with standard chromophores at concentrations≦1%. Alternatively or in addition, the material may contain blue lightblocking chromophores, e.g., yellow dyes which block the desired regionof the blue-light spectrum. Suitable materials are generally resistantto damage, e.g., surface abrasion, cracking, or hazing, incurred bymechanical trauma under standard implantation techniques.

The components of the modular IOL may be formed by conventionaltechniques such as molding, cutting, milling, etching or a combinationthereof.

As an alternative to mechanical attachment, chemical attraction betweenthe primary and secondary components may be utilized. Using similarmaterials with a smooth surface finish may facilitate chemicalattraction. Chemical attraction may be enhanced by surface activationtechniques such as plasma or chemical activation. In some instances, itmay be desirable to reduce chemical attraction to avoid sticking betweenthe materials and rely more on mechanical attachment for stability. Inthis case, the primary and secondary components may be formed ofdissimilar materials or otherwise have adjacent surfaces that do nothave a chemical attraction.

With reference to FIGS. 14-14C, an alternative modular IOL 140 is shownin front, sectional and detailed views, respectively. FIG. 14A shows across-sectional view taken along line A-A in FIG. 14, FIG. 14B shows across sectional view taken along line B-B in FIG. 14, and FIG. 140 showsa detail view of circle C in FIG. 14B. Modular IOL 140 may include aprimary lens 50 with haptics 54 and a secondary lens 60. The interfacingsurfaces of the primary lens 50 (anterior surface) and secondary lens 60(posterior surface) may be in intimate contact as best seen in FIGS. 14Aand 14B. Maintaining intimate contact (i.e., avoiding a gap) ormaintaining a consistent gap between the interfacing surfaces of theprimary lens 50 and the secondary lens 60 may reduce the likelihood ofinduced astigmatism. In some embodiments, however, a substance (e.g., anadhesive agent) may be disposed between the respective surfaces oflenses 50 and 60. A circular extension may be formed in the secondarylens 60, with a correspondingly sized and shaped circular recess formedin the primary lens 50 to form an interference fit therebetween, thussecurely connecting the two components. The depth of the recess in theprimary lens 50 may be a fraction of the thickness of the secondary lens60, with a circular extension of the secondary lens 60 extending over aportion of the primary lens 50, thereby forming an overlap joint 142 asbest seen in FIG. 14C. The overlap joint 142 may extend 360 degreesaround the circumference of the secondary lens 60 as shown, or afraction thereof. The circular extension of the secondary lens 60 risesabove the anterior surface of the primary lens 50 to form a raisedportion. In some embodiments, the raised portion may have a radiallytapering configuration. The raised portion may be radially compressedwith forceps to facilitate connection and disconnection of the primarylens 50 and the secondary lens 60. Using radial compression to insertthe secondary lens 60 into the primary lens 50 reduces theanterior-posterior forces applied to the capsular bag during insertion,thereby reducing the risk of capsular rupture.

With reference to FIGS. 15-15D, an alternative modular IOL 150 is shownin front, sectional and detailed views, respectively. FIG. 15A shows across-sectional view taken along line A-A in FIG. 15, FIG. 15B shows across sectional view taken along line B-B in FIG. 15, FIG. 15C shows adetail view of circle C in FIG. 15B, and FIG. 15D shows an alternativedetail view of circle C in FIG. 15B. Modular IOL 150 may include aprimary lens 50 with haptics 54 and a secondary lens 60. The interfacingsurfaces of the primary lens 50 (anterior surface) and secondary lens 60(posterior surface) may be in intimate contact as best seen in FIGS. 15Aand 15B. The primary lens 50 may include a recess defining a wall intowhich the correspondingly sized and shaped circular secondary lens 60may be placed. The wall defined by the recess in the primary lens 50 mayextend around the entire perimeter of the primary lens with theexception of two diametrically opposed gaps 152. The gaps 152 thusexpose the perimeter edge of the secondary lens 60 as seen in FIG. 15Ato facilitate insertion and removal by radial compression of thesecondary lens 60 using forceps, for example. The remainder of the walldefined by the recess in the primary lens provides for a flush joint asseen in FIGS. 15B and 15C, where the anterior surface of the secondarylens 60 may be flush with the anterior surface of the primary lens 50.As seen in FIG. 150, the wall defined by the recess in the primary lens50 and the interfacing edge of the secondary lens 60 may be cantedinwardly to provide a joint 154 with positive mechanical capture andsecure connection therebetween. Alternatively, as seen in FIG. 15D, thewall defined by the recess in the primary lens 50 and the interfacingedge of the secondary lens 60 may be “S” shaped to provide a joint 156with positive mechanical capture and secure connection therebetween.Alternative interlocking geometries may be employed.

With reference to FIGS. 16-16D, an alternative modular IOL 160 is shownin front, sectional and detailed views, respectively. FIG. 16A shows across-sectional view taken along line A-A in FIG. 16, FIG. 16B shows across sectional view taken along line B-B in FIG. 16, FIG. 16C shows adetail view of circle C in FIG. 16B, and FIG. 16D shows a detail view ofcircle D in FIG. 16A. Modular IOL 160 may be configured similar tomodular IOL 150 shown in FIGS. 15-15D with primary lens 50 including arecess defining a wall into which the correspondingly sized and shapedcircular secondary lens 60 may be placed. However, in this embodiment,an angular gap 162 (rather than gap 152) is provided along a fraction ofthe perimeter of the secondary lens 60. The wall defined by acircumferential portion of the perimeter edge of the secondary lens 60may have the same geometry as the wall defined by the recess in theprimary lens 50 to provide a flush joint 154 as best seen in FIG. 16C.The wall defined by another (e.g., the remainder) circumferentialportion of the perimeter edge of the secondary lens 60 may have a moreinwardly angled geometry to provide an angled gap 162 as best seen inFIG. 16D. The angled gap 162 thus exposes the perimeter edge of thesecondary lens 60 as seen in FIG. 16D into which forceps may be placedto facilitate insertion and removal by radial compression of thesecondary lens 60. Alternative gap geometries may be employed.

With reference to FIGS. 17-17C, an alternative modular IOL 170 is shownin front, sectional, detailed and isometric views, respectively. FIG.17A shows a cross-sectional view taken along line A-A in FIG. 17, FIG.17B shows a detail view of circle B in FIG. 17A, and FIG. 17C shows anisometric view of the assembled components. Modular IOL 170 may beconfigured similar to modular IOL 150 shown in FIGS. 15-15D with primarylens 50 including a recess defining a wall into which thecorrespondingly sized and shaped circular secondary lens 60 may beplaced. However, in this embodiment, the wall defining the recess in theprimary lens 50 includes a portion thereof that is milled down to definetwo diametrically opposed tabs 172. The inside circumferential walls ofthe tabs 172 provide for a flush joint 174 as seen in FIG. 17B, suchthat the anterior surface of the secondary lens 60 is flush with theanterior surface of the primary lens 50. The interface of the joint 174along the tabs 172 may be canted, “S” shaped, or “C” shaped as shown,for example. Elsewhere along the perimeter, away from the tabs 172, inthe area where the wall is milled down, the perimeter edge of thesecondary lens 60 is exposed as seen in FIG. 17C, to facilitateinsertion and removal of the secondary lens 60 by radial compressionthereof using forceps, for example.

With reference to FIGS. 18-18C, an alternative modular IOL 180 is shownin front, sectional, detailed and isometric views, respectively. FIG.18A shows a cross-sectional view taken along line A-A in FIG. 18, FIG.18B shows a detail view of circle B in FIG. 18A, and FIG. 180 shows anisometric view of the assembled components. Modular IOL 180 may beconfigured similar to modular IOL 170 shown in FIGS. 17-17C with primarylens 50 including a recess defining a partial wall into which thecorrespondingly sized and shaped circular secondary lens 60 may beplaced, interlocking via flush joint 174 in tabs 172. However, in thisembodiment, grasping recesses or holes 182 are provided in each of thetabs 172 and in the adjacent portions of secondary lens 60. In oneembodiment, the grasping recesses or holes 182 may not extend through anentire thickness of primary 50 and secondary 60 lenses. The graspingholes 182 in the secondary lens 60 facilitate insertion and removal byradial compression of the secondary lens 60 using forceps, for example.Adjacent grasping holes 182 in the tab portion 172 and the secondarylens 60 may be pulled together or pushed apart in a radial direction tofacilitate connection and disconnection, respectively, of the joint 174using forceps, for example.

Using radial forces applied via the grasping holes 182 to connect anddisconnect (or lock and unlock) the joint 174 between the primary lens50 and the secondary lens 60 reduces the anterior-posterior forcesapplied to the capsular bag, thereby reducing the risk of capsularrupture. Grasping holes 182 may also be used to facilitate connectingand disconnecting different interlocking geometries while minimizinganterior-posterior forces. For example, a recess in the primary lens 50may include internal threads that engage corresponding external threadson the perimeter edge of the secondary lens 60. In this embodiment,forceps inserted into the grasping holes 182 may be used to facilitaterotation of the secondary lens 60 relative to the primary lens 50 toscrew and unscrew the primary 50 and secondary 60 lenses. In analternative embodiment, a keyed extension of the secondary lens 60 maybe inserted into an keyed opening in the primary lens 50 and rotatedusing forceps inserted into the grasping holes 182 to lock and unlockthe primary 50 and secondary 60 lenses. In another alternativeembodiment, forceps or the like may be inserted posteriorly through ahole in the secondary lens 60 to grasp an anterior protrusion on theprimary lens 50 like a handle (not shown), followed by applyingposterior pressure to the secondary lens 60 while holding the primarylens 50 stationary. The grasping holes 182 may also be used to rotatethe secondary lens 60 relative to the primary lens 50 for purposes ofrotational adjustment in toric applications, for example.

With reference to FIGS. 19-19D, an alternative modular IOL 190 is shownin front, sectional, detailed, isometric exploded and isometricassembled views, respectively. FIG. 19A shows a cross-sectional viewtaken along line A-A in FIG. 19, FIG. 19B shows a detail view of circleB in FIG. 19A, FIG. 19C shows an exploded isometric view of thecomponents, and FIG. 19D shows an assembled isometric view of thecomponents. Modular IOL 190 differs from some of the previouslydescribed embodiments in that the primary component serves as a base 55but does not necessarily provide for optical correction, whereas thesecondary component serves as a lens 65 and provides for opticalcorrection. Base 55 may be configured in the shape of an annulus or ringwith a center opening 57 extending therethrough in an anterior-posteriordirection. In some embodiments, base 55 may not define a complete ringor annulus. Base 55 may also include haptics 59, which are similar infunction to haptics 54 described previously but differ in geometricconfiguration. Generally, haptics 54/59 function to center the base 55in the capsular bag. Such haptics may also be configured to applyoutward tension against the inside equatorial surface of the capsularbag, similar to capsular tension rings, to aid in symmetric healing andmaintain centration of the base. The haptics 59 may include one or moreopenings therein.

Because the base 55 includes a center opening 57, the posterior opticalsurface of the lens 65 is not in contact with the base 55. A circularextension may be formed in the lens 65, with a correspondingly sized andshaped circular recess formed in the base 55 to form a ledge on the base55 and an overlapping joint 192 with an interference and/or friction fittherebetween, thus securely connecting the two components.Alternatively, the shape of the overlapping joint 192 may form a cantedangle or an “S” shape as described previously to form an interlocktherebetween. The joint or junction 192 may include a modified surfaceto reduce light scattering caused by the junction 192. For example, oneor both of the interfacing surfaces of the joint 192 may be partially tototally opaque or frosted (i.e., roughened surface) to reduce lightscattering caused by the junction 192.

The depth of the recess in the base 55 may be the same thickness of thecircular extension of the lens 65 such that the anterior surface of thelens 65 and the anterior surface of the base 55 are flush as best seenin FIG. 19B. With this arrangement, the posterior surface of the lens 65extends more posteriorly than the anterior surface of the base 55. Insome embodiments, however, the anterior surface of lens 65 may bedisposed relatively higher or lower than the anterior surface of base55. The dimensions of the recess and the corresponding ledge in the base55 may be selected relative to the thickness of the lens 65 such that atleast a portion of the posterior-most surface of the lens 65 is coplanarwith the posterior-most surface of the base 55, or such that at least aportion of the posterior-most surface of the lens 65 is more posteriorthan the posterior-most surface of the base 55.

As with prior embodiments, the lens may be exchanged for a differentlens either intra-operatively or post-operatively. This may bedesirable, for example, if the first lens does not provide for thedesired refractive correction, in which case the first lens may beexchanged for a second lens with a different refractive correction,without disturbing the lens capsule. In cases where the lens 65 does nothave the desired optical alignment due to movement or misalignment ofthe base, for example, it may be exchanged for a different lens with anoptical portion that is manufactured such that it is offset relative tothe base 55. For example, the optical portion of the second lens may beoffset in a rotational, lateral and/or axial direction, similar to theembodiments described with reference to FIGS. 9A-9D. This generalconcept may be applied to other embodiments herein where the secondarycomponent (e.g., lens) has limited positional adjustability relative tothe primary component (e.g., base).

A number of advantages are associated with the general configuration ofthis embodiment, some of which are mentioned hereinafter. For example,because the posterior optical surface of the lens 65 is not in contactwith the base 55, the potential for debris entrapment therebetween iseliminated. Also, by way of example, because the base 55 includes acenter opening 57 that is devoid of material, the base 55 may be rolledinto a smaller diameter than a primary lens 50 as described previouslyto facilitate delivery through a smaller incision in the cornea.Alternatively, the base 55 may have a larger outside diameter and berolled into a similar diameter as primary lens 50. For example, the baselens 55 may have an outside diameter (excluding haptics) ofapproximately 8 mm and be rolled into the same diameter as a primarylens 50 with an outside diameter 6 mm. This may allow at least a portionof the junction between the base 55 and lens 65 to be moved radiallyoutward away from the circumferential perimeter of the capsulorhexis,which typically has a diameter of 5-6 mm. Moving at least a portion ofthe junction between the base 55 and the lens 65 radially outward fromthe perimeter of the capsulorhexis may reduce the amount of the junctionthat is in the field of view and thus reduce the potential for lightscattering or optical aberrations (e.g., dysphotopsias) created thereby.Of course, notwithstanding this example, any suitable dimensions may beselected to provide a gap between the lens 65 and the perimeter edge ofthe capsulorhexis in order to mitigate the need to manipulate the lenscapsule to connect or disconnect the lens 65 to or from the base 55.

With reference to FIGS. 20-20D, an alternative modular IOL 200 is shownin front, sectional, detailed, isometric exploded and isometricassembled views, respectively. FIG. 20A shows a cross-sectional viewtaken along line A-A in FIG. 20, FIG. 20B shows a detail view of circleB in FIG. 20A, FIG. 200 shows an exploded isometric view of thecomponents, and FIG. 20D shows an assembled isometric view of thecomponents. Modular IOL 200 includes a base 55 with associated haptics59 and a lens 65. The base 55 includes a center hole 57 such that theposterior optical surface of the lens 65 is not in contact with the base55. The lens 65 includes a circular extension that is sized and shapedto fit in a circular recess formed in the base 55 to form a ledge on thebase 55 and an overlapping joint 202. The overlapping joint 202 may beconfigured with an “S” shaped interface to securely connect the twocomponents. Thus, modular IOL 200 is similar to modular IOL 190, exceptthat the joint 202 between the base 55 and the lens 65 may include apeg-and-hole arrangement. In this arrangement, a pair of diametricallyopposed pegs 204 may extend posteriorly from the posterior perimeter ofthe lens 65 and fit within a selected pair of holes 206 from a series ofholes 206 formed in the ledge of the joint 202 in the base 55.

FIGS. 20E-20I show additional detail of modular IOL 200. FIG. 20E showsa side view of the lens 65, FIG. 20F shows a rear view of the posteriorsurface of the lens 65, FIG. 20G is a detailed view of circle G in FIG.20E, FIG. 20H is a front view of the anterior surface of the base 55,and FIG. 20I is a detailed view of circle I in FIG. 20H. As seen inFIGS. 20E-20F, a pair of diametrically opposed pegs 204 may extendposteriorly from the posterior perimeter of the lens 65. As seen inFIGS. 20H-20I, the inside diameter of the base 55 along the ledge of thejoint 202 includes a series of holes 206, into a selected pair of whichthe pair of pegs 204 may be inserted. With this arrangement, the lens 65may be selectively rotated relative to the base 55 for purposes ofrotational adjustment in toric applications, for example.

With reference to FIGS. 21-21E, an alternative modular IOL 210 is shownin front, sectional, detailed and Isometric views, respectively. FIGS.21A and 21B show a cross-sectional views taken along line A-A and lineB-B, respectively, in FIG. 21. FIGS. 21C and 21D show detail views ofcircle C in FIG. 21A and circle D in FIG. 21B, respectively. FIG. 21Eshows an isometric view of the assembled components of the modular IOL210. Modular IOL 210 may be configured similar to a combination ofmodular IOL 190 shown in FIGS. 19-19D and modular IOL 170 shown in FIGS.17-17C. Like modular IOL 190, modular IOL 210 includes a base 55configured in the shape of an annulus or ring with a center opening anda recess defining a wall into which the correspondingly sized and shapedcircular lens 65 may be placed. Like modular IOL 170, the wall definingthe recess extends along the inside perimeter of the base 55, with aportion thereof milled down to define two diametrically opposed tabs212. The inside circumferential walls of the tabs 212 provide for aflush joint 214 as seen in FIG. 21C, such that the anterior surface ofthe lens 65 is flush with the anterior surface of the base 55. Theinterface of the joint 214 along the tabs 212 may be canted, “S” shaped,or “C” shaped as shown, for example. Elsewhere along the perimeter, awayfrom the tabs 212, in the area where the wall is milled down, theperimeter edge of the lens 65 is exposed as seen in FIG. 21D, tofacilitate insertion and removal of the lens 65 by radial compressionusing forceps, for example.

With reference to FIGS. 22-22D, an alternative modular IOL 220 is shownin front, sectional, and detailed views, respectively. FIG. 22A shows across-sectional view taken along line A-A in FIG. 22, FIG. 22B across-sectional view taken along line B-B in FIG. 22, FIG. 22C shows adetail view of circle C in FIG. 22A, and FIG. 22D shows a detail view ofcircle D in FIG. 22B. Modular IOL 220 includes a base 55 with associatedhaptics 59 and a lens 65. The base 55 includes a center hole such thatthe posterior optical surface of the lens 65 is not in contact with thebase 55. The perimeter of the lens 65 is sized and shaped to fit in acircular recess formed in the base 55 to form a ledge on the base 55 anda flush joint 222. The flush joint 222 may be configured with an “S”shaped interface to securely connect the two components. A pair of pegs224 extend anteriorly from the base 55 adjacent the inside perimeterthereof, and through a pair of arc-shaped slots 226 adjacent theperimeter of the lens 65. The arc-shaped slots may extend along afraction of the circumference of the lens 65 as shown in FIG. 22. Withthis arrangement, the lens 65 may be selectively rotated relative to thebase 55 for purposes of rotational adjustment in toric applications, forexample.

The pegs 224 may be sized and configured to rise above the anteriorsurface of the lens 65 as shown in FIG. 22C. Forceps or the like may beinserted posteriorly through the arc-shaped slots 226 in the lens 65 tograsp the pegs 224 like a handle, followed by applying posteriorpressure to the lens 65 while holding the pegs 224 stationary. Byholding the pegs 224 and thus stabilizing the base 55 during connectionof the lens 65 to the base 55, anterior-posterior forces applied to thecapsular bag are reduced, thereby reducing the risk of capsular rupture.

With reference FIGS. 23A-23D, a lens removal system for a modular IOLaccording to an embodiment of the present disclosure is shownschematically. FIGS. 23A and 23B are side and top views, respectively,of the lens removal system. FIGS. 23C and 23D are top views showing howthe lens removal system may be used to remove lens 60/65. The lensremoval or extractor system may include a cannula 230 and a pair offorceps 235. The cannula 230 may include a lumen sized to slidablyreceive the forceps 235. The cannula 230 may include a tubular shaftportion 232 and a contoured distal opening 234. The cannula 230 may beformed and configured similar to conventional IOL insertion devices, forexample. The forceps 235 include a pair of atraumatic grasping tips 237and a tubular shaft 239. The tubular shaft 239 may be advanced tocompress the tips 237 and grasp the lens 60/65. The forceps 235 may beformed and configured similar to conventional ophthalmology forceps, forexample, except that the tips 237 may be formed of or covered by arelatively soft polymeric material to avoid damage to the lens 60/65.Generally, any devices used to manipulate the modular IOL componentsdescribed herein may be formed of or covered by a relatively softpolymeric material to avoid damage to the components thereof.

With reference to FIGS. 23C and 23D, the cannula 230 may be insertedthrough a corneal incision until its distal end is adjacent thecapsulorhexis. The forceps 235 may be inserted into and through thecannula 230, until the distal tips 237 extend distally beyond the distalend of the cannula 230. The lens 60/65 to be extracted may be graspedwith the forceps 235 as shown in FIG. 23C. With the lens 60/65 securelyheld by the forceps 235, the forceps 235 may be retracted proximallyinto the cannula 230. As the forceps 235 are retracted into the cannula230, the lens 60/65 enters the contoured opening 234. The contouredopening 234 encourages the edges of the lens 60/65 to roll and fold asseen in FIG. 23D. Complete retraction of the forceps 235 into thecannula 230 thus captures the lens 60/65 safely in the lumen of thecannula 230 after which it may be removed from the eye. A similarapproach may also be used to insert the lens 60/65, reversing therelevant steps.

FIGS. 24-26 describe example methods of using modular IOLs according toembodiments of the present disclosure. Although described with referenceto a primary lens and a secondary lens by way of example, notnecessarily limitation, the same or similar methods may be applied othermodular IOL embodiments, including modular IOL embodiments describedherein that comprise a base and a lens.

With reference to FIG. 24, a method for using a modular IOL according toan embodiment of the present disclosure is shown in a schematic flowchart. In this example, the secondary lens may be exchanged in the eventof a sub-optimal optical result detected intra-operatively. An IOLimplant procedure, such as cataract surgery, may be started 110according to conventional practice. The native lens may then be prepared112 to receive a modular IOL using conventional steps such as makingcorneal access incisions, cutting the capsulorhexis in the anteriorcapsular bag and removing the cataract lens by phacoemulsification. Thebase lens (i.e., primary lens 50) is then placed 114 in the lenscapsule. The secondary lens (i.e., secondary lens 60) is then placed 116on the base lens within the perimeter of the capsulorhexis withouttouching or otherwise disturbing the capsular bag. The attachment meansis then engaged 118 to releasably connect the secondary lens to the baselens. Alternatively, the secondary lens may be attached to the base lensbefore placement in the lens capsule, such that the base lens and thesecondary lens are inserted together as a unit. With both the base lensand the secondary lens in place, the optical result may be measured 120,for example by intra-operative aberrometry. The optical result may takeinto consideration refractive correction, centricity, toric correction,etc. A decision 122 is then made as to whether the optical result isoptimal or sub-optimal. If the optical result is optimal or otherwiseadequate, the IOL procedure is completed 124. However, if the opticalresult is sub-optimal or otherwise inadequate, the attachment means maybe disengaged 126 and the secondary lens may be removed 128. A differentsecondary lens may be then placed 116 on the base lens, following thesame subsequent steps as shown. The different secondary lens may have,for example, a different refractive power to correct refractive error, adifferent offset to correct for decentration, or a different toric powerto correct for toric error.

With reference to FIG. 25, an alternative method for using a modular IOLaccording to an embodiment of the present disclosure is shown in aschematic flow chart. In this example, the secondary lens may beexchanged in the event of a sub-optimal optical result detectedpost-operatively. The same steps 110-118, and 124 may be performed asdescribed previously, except that the patient is allowed to acclimate130 to the modular IOL for a period of 1-4 weeks or more, for example.Upon a return visit, the optical result is measured 120 and adetermination 122 is made as to whether the optical result is optimal orsub-optimal. If the optical result is optimal or otherwise adequate, theprocedure is stopped 132. If the optical result is sub-optimal orotherwise inadequate, a revision procedure may be initiated 134 toreplace the secondary lens following steps 126, 128, 116 and 118 asdescribed previously.

This method allows the lens capsule to heal before deciding whether theoptical result is sufficient, which may be advantageous to the extentthe healing process alters the position of the primary and/or secondarylens. This method may also be applied on a chronic basis, where theoptical needs or desires of the patient change over the course of alonger period of time (e.g., >1 year). In this example, the patient mayrequire or desire a different correction such as a stronger refractivecorrection, a toric correction, or a multifocal correction, each ofwhich may be addressed with a different secondary lens.

With reference to FIG. 26, another alternative method for using amodular IOL according to an embodiment of the present disclosure isshown in a schematic flow chart. In this example, the secondary lens maybe implanted in a patient 138 having a pre-existing IOL that isoptically sub-optimal or otherwise doesn't meet the needs and desires ofthe patient. After the procedure starts 110, an attachment mechanism maybe formed in-situ in the pre-existing (base) IOL (step 140) using laseretching, for example, to form a groove as described previously.Formation of the groove may be performed within the perimeter of thepreviously cut capsulorhexis to avoid touching or otherwise disturbingthe lens capsule. The secondary lens may then be placed 116 on the baselens within the perimeter of the capsulorhexis, and the attachment meansmay be engaged 118 to connect the secondary lens to the base lens, andthe procedure may be completed 124 as described previously.

With reference to FIGS. 27-27D, an alternative modular IOL 270 is shownin front, sectional and detailed views, respectively. FIGS. 27A and 27Bshow cross-sectional views taken along line A-A and line B-B,respectively, in FIG. 27. FIGS. 27C and 27D show detail views of circleC in FIG. 27A and circle D FIG. 27B, respectively. Modular IOL 270 maybe configured similar to modular IOL 210 shown in FIGS. 21-21D. Likemodular IOL 210, modular IOL 270 includes a base 55 configured in theshape of an annulus or ring with a center opening and a recess defininga wall into which the correspondingly sized and shaped circular lens 65may be placed. Also like modular IOL 210, the wall defining the recessextends along the inside perimeter of the base 55, with a portionthereof milled down to define two diametrically opposed tabs 272. Theinside circumferential walls of the tabs 272 provide for a flush joint274 as seen in FIG. 27C, such that the anterior surface of the lens 65is flush with the anterior surface of the base 55. The interface of thejoint 274 along the tabs 272 may be canted, “S” shaped, or “C” shaped asshown, for example. Elsewhere along the perimeter, away from the tabs272, in the area where the wall is milled down, the perimeter edge ofthe lens 65 is exposed as seen in FIG. 27D, to facilitate insertion andremoval of the lens 65 by radial compression using forceps, for example.

Because the base 55 includes a center opening that is devoid ofmaterial, the base 55 may have a larger outside optic diameter(excluding haptics) of approximately 8 mm, for example, and still berolled into a delivery profile that is sufficiently small to fit througha corneal incision of less than approximately 2.4 mm, for example. Thismay allow at least a portion of the junction between the base 55 andlens 65 to be moved radially outward away from the circumferentialperimeter of the capsulorhexis, which typically has a diameter of 5-6mm. Moving at least a portion of the junction between the base 55 andthe lens 65 radially outward from the perimeter of the capsulorhexis mayreduce the amount of the junction that is in the field of view and thusreduce the potential for light scattering or optical aberrations (e.g.,dysphotopsias) created thereby.

To further illustrate this advantage, consider a standard (singlecomponent) IOL, which typically has an optic diameter of conventionallenses is 6 mm. An IOL with a 6 mm diameter optic may be rolled anddelivered through a 2.2 mm corneal incision. In order to secure thestandard IOL in the capsular bag, the capsulorhexis is typically sizedto allow the capsular bag to fully capture the standard IOL after thebag collapses and heals down. This drives surgeons to form acapsulorhexis having a diameter of approximately 4.5 mm to 5.5 mm.

Now consider IOL 270 by comparison. The modular (two piece) nature ofIOL 270 and the hole in the base 55 allow both components (base 55 andlens 65) to be rolled and delivered through a small corneal incision(e.g., 2.2 mm), but don't require a capsulorhexis of 4.5 mm to 5.5 mm.Rather, because the base has a diameter of 8 mm (excluding haptics), thecapsulorhexis diameter may be larger (e.g., 6.0 mm to 6.5 mm), whichallows the lens 65 to comfortably fit inside the perimeter of thecapsulorhexis and allows the junction 274 to be more peripheral tofurther minimize light scatter. Of course, notwithstanding theseexamples, any suitable dimensions may be selected to provide a gapbetween the lens 65 and the perimeter edge of the capsulorhexis in orderto mitigate the need to manipulate the lens capsule to connect ordisconnect the lens 65 to or from the base 55.

We claim:
 1. An intraocular lens system, comprising: a. an intraocularprimary component having a body, one or more haptics, a center throughhole extending in an anterior-posterior direction through the body toform a continuous annular ring having an inside perimeter, and acontinuous recess extending around an entirety of the inside perimeter,the continuous recess being defined by an anterior-facing posterior walland a radially-inward-facing lateral wall, wherein theradially-inward-facing lateral wall includes diametrically spacedextensions extending anteriorly of and radially inward from theradially-inward-facing lateral wall, and the primary component isconfigured to fit within a lens capsule; and b. an intraocular secondarycomponent having an optical body, wherein the secondary component isconfigured for insertion into the continuous recess of the primarycomponent such that an entire posterior periphery of the secondarycomponent contacts the anterior-facing posterior wall of the continuousrecess, only the diametrically spaced extensions extend over an anteriorperipheral edge of the secondary component at discrete, diametricallyspaced apart junctions so as to interlock to thereby limit relativeanterior and posterior movement between the primary and secondarycomponents, and the secondary component requires radial compression forinsertion into the primary component; c. wherein, in an implantedconfiguration, the intraocular lens system is configured to provideoptical correction to an eye solely via the optical body of theintraocular secondary component, an anterior surface of each of thediametrically spaced extensions is flush and even with an anteriorsurface of the optical body of the secondary component, and theradially-inward-facing lateral wall of the continuous recess, except atthe diametrically spaced extensions, is posterior to the anteriorperipheral edge of the secondary component, such that the anteriorperipheral edge is exposed between the diametrically spaced extensions.2. A system as in claim 1, wherein a posterior-most optical surface ofthe secondary component extends more posteriorly than an anteriorsurface of the primary component.
 3. A system as in claim 1, wherein theprimary component is a base and the secondary component is a lens.
 4. Asystem as in claim 1, wherein the secondary component excludes haptics.5. An intraocular lens system, comprising: a. an intraocular primarycomponent having a body and one or more haptics, wherein the body isannular and defines a through opening having an inside perimeter, thebody further includes a continuous recess extending around an entiretyof the inside perimeter, the continuous recess being defined by ananterior-facing posterior wall and a radially-inward-facing lateralwall, and wherein the body further includes diametrically spacedextensions extending anteriorly of and radially inward from theradially-inward-facing lateral wall, the diametrically spaced extensionsterminating with a radially-inward-facing concave free edge; and b. anintraocular secondary component having an optical body, wherein thesecondary component is releasably attachable to the primary component byinsertion of the secondary component into the continuous recess of theprimary component such that an entire posterior periphery of thesecondary component contacts the anterior-facing posterior wall of therecess, the diametrically spaced extensions extend over an anteriorperipheral portion of the secondary component at discrete, diametricallyspaced apart junctions, so as to interlock to thereby limit relativeanterior and posterior movement between the primary and the secondcomponents and to leave the anterior peripheral portion exposed betweenthe diametrically spaced extensions, and the secondary component iscompressible for releasable attachment to the primary component; c.wherein the intraocular lens system is configured to provide opticalcorrection to an eye solely via the optical body of the secondarycomponent.
 6. A system as in claim 5, further including a plurality ofsecondary components, each of the secondary components being configuredto interchangeably and releasably attach to the primary component.
 7. Asystem as in claim 6, wherein one of the secondary components providesan optical correction different from an optical correction provided byanother of the secondary components.
 8. A system as in claim 5, whereinthe optical correction includes a refractive correction.
 9. A system asin claim 5, wherein the optical correction includes a toric correction.10. A system as in claim 5, wherein the optical correction includes amultifocal correction.
 11. A system as in claim 5, wherein the opticalbody is centered over the through opening.
 12. An intraocular lenssystem, comprising: a. a base having a body, a plurality of hapticsextending from the body, a center opening extending in ananterior-posterior direction through the body to form a continuousannular ring having an insider perimeter, a continuous recess extendingaround an entirety of the inside perimeter, the continuous recess beingdefined by an anterior-facing posterior wall and aradially-inward-facing lateral wall, wherein the radially-inward-facinglateral wall includes diametrically spaced extensions extendinganteriorly of and radially inward from the radially-inward-facinglateral wall, the diametrically spaced extensions terminating with aradially-inward-facing concave free edge, and the base being configuredto fit within a lens capsule; and b. a lens having an optical body,wherein the lens is releasably attachable to the base by insertion ofthe lens into the continuous recess of the base such that an entireposterior periphery of the lens contacts the anterior-facing posteriorwall of the recess, the diametrically spaced extensions extend over ananterior peripheral portion of the lens to form discrete, diametricallyspaced apart junctions so as to interlock to thereby limit relativeanterior and posterior movement between the base and the lens, and thelens is radially compressible for releasable attachment to the base; c.wherein the intraocular lens system is configured to provide opticalcorrection to an eye solely via the lens, a surface of each of thediametrically spaced extensions is even with a portion of an anteriorsurface of the lens, and the radially-inward-facing lateral wall of thecontinuous recess, except at the diametrically spaced extensions,exposes a portion of the anterior peripheral portion of the lens.
 13. Asystem as in claim 12, wherein the base is configured for insertionthrough a capsulorhexis formed in the lens capsule.
 14. A system as inclaim 13, wherein the discrete, diametrically spaced apart junctionsreside radially within a perimeter of the capsulorhexis when the base iswithin the lens capsule.
 15. A system as in claim 12, wherein the lensis positioned over the center opening.
 16. A system as in claim 12,further including a plurality of lenses that are configured tointerchangeably and releasably attach to the base.
 17. A system as inclaim 16, wherein at least one of the lenses provides an opticalcorrection different from an optical correction provided by another ofthe lenses.
 18. A system as in claim 12, wherein only the diametricallyspaced extensions extend over the anterior peripheral portion of thelens to interlock with the anterior peripheral portion of the lens. 19.A system as in claim 1, wherein the diametrically spaced extensionsterminate with a radially-inward facing concave free edge.
 20. A systemas in claim 19, wherein the radially-inward-facing concave free edge isflush and even with the anterior peripheral edge of the secondarycomponent.
 21. A system as in claim 5, wherein only the diametricallyspaced extensions extend anteriorly of the anterior peripheral portionof the secondary component and interlock with the anterior peripheralportion of the secondary component.
 22. A system as in claim 5, whereinthe radially-inward facing concave free edges of the diametricallyspaced extensions are even with a portion of the anterior surface of thesecondary component.
 23. A system as in claim 5, wherein an anteriorsurface of each of the diametrically spaced extensions is flush and evenwith an anterior surface of the secondary component.